1. Field of the Invention
The invention relates to a packer apparatus which is adapted for use in corrosive environments within subterranean wells.
2. Description of the Prior Art
In-situ mining and in-situ leaching are synonymous processes employed to extract minerals from the earth without the removal of the ore body. These processes involve injection of a suitable fluid into the ore deposit in order to dissolve the valuable mineral, and lifting the mineral-laden fluid to the surface for extraction. Although somewhat similar to water flooding operations, in-situ mining is distinctly different from water flooding because of the exposure to and use of highly corrosive fluids, often called lixiviants, such as sulfuric acid solutions. These solutions are injected into an injection well for removal of an ore deposit, such as copper or uranium, from within one of several production wells, which may encircle the injection well. The corrosive fluids are chosen to dissolve portions of the ore body. Any lixiviant capable of reacting with and dissolving copper, unranium or other minerals usually will be very corrosive to conventional oil field equipment.
Because of the corrosive environment of such wells, the casing string must be made of a material which is resistant to the adverse effects of highly corrosive materials, such as sulfuric acid solutions. Typical of such materials is casing made of a fiberglass reinforced epoxy resin. However, because of the malleable nature of such casing, conventional packers, utilizing slip assemblies having teeth members protruding thereon for grasping around the internal diameter of the casing, are undesirable for such purposes.
The present invention provides a packer assembly which may be anchored in such a well without the use of slips, by utilization of a collet mechanism which is received within a recess defined on the casing string for anchoring engagement of the packer assembly. The metallic components of the packer assembly preferably may be made of stainless steel, or other non-corrosive material.